Giddy physicists shouted hallelujah yesterday over the discovery of the so-called “God particle,” the holy grail of scientific research that could help explain the mystery of size and shape in the universe.

“We have now found the missing cornerstone of particle physics,” a delighted Rolf Heuer, director of the European Center for Nuclear Research, told scientists gathered in Geneva, Switzerland.

With the help of the world’s biggest atom smasher, a $10 billion supercollider on the Swiss-French border, researchers achieved a breakthrough that was 40 years in the making, an accomplishment that brought the usually staid scientists to their feet in applause.

Heuer stopped short of saying the particle is the long-sought Higgs boson, but said it could lead to a new understanding of how the universe began.

“As a layman, I think we did it,” Heuer told the elated crowd. “We have a discovery. We have observed a new particle that is consistent with a Higgs boson.”

The atom has been dubbed the “God particle” because of its scientific importance. Scientists say the particle gives everything in the universe its mass.